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| author |  Peter Zijlstra <peterz@infradead.org>
| 2023-01-12 20:43:36 +0100 |
|---|---|---|
| committer |  Ingo Molnar <mingo@kernel.org>
| 2023-01-13 11:48:15 +0100 |
| commit | e80a48bade619ec5a92230b3d4ae84bfc2746822 (patch) | |
| tree | c0781002ed2ea989994d430ab180546c8ac3c653 /arch/x86/coco/tdx/tdx.c | |
| parent | arch/idle: Change arch_cpu_idle() behavior: always exit with IRQs disabled (diff) | |
| download | linux-e80a48bade619ec5a92230b3d4ae84bfc2746822.tar.gz linux-e80a48bade619ec5a92230b3d4ae84bfc2746822.tar.bz2 linux-e80a48bade619ec5a92230b3d4ae84bfc2746822.zip | |
x86/tdx: Remove TDX_HCALL_ISSUE_STI
Now that arch_cpu_idle() is expected to return with IRQs disabled,
avoid the useless STI/CLI dance.
Per the specs this is supposed to work, but nobody has yet relied up
this behaviour so broken implementations are possible.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195540.682137572@infradead.org
Diffstat (limited to 'arch/x86/coco/tdx/tdx.c')
| -rw-r--r-- | arch/x86/coco/tdx/tdx.c | 23 |
1 files changed, 4 insertions, 19 deletions
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index f4a59c365321..8804174aef1a 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -220,7 +220,7 @@ static int ve_instr_len(struct ve_info *ve) } } -static u64 __cpuidle __halt(const bool irq_disabled, const bool do_sti) +static u64 __cpuidle __halt(const bool irq_disabled) { struct tdx_hypercall_args args = { .r10 = TDX_HYPERCALL_STANDARD, @@ -240,20 +240,14 @@ static u64 __cpuidle __halt(const bool irq_disabled, const bool do_sti) * can keep the vCPU in virtual HLT, even if an IRQ is * pending, without hanging/breaking the guest. */ - return __tdx_hypercall(&args, do_sti ? TDX_HCALL_ISSUE_STI : 0); + return __tdx_hypercall(&args, 0); } static int handle_halt(struct ve_info *ve) { - /* - * Since non safe halt is mainly used in CPU offlining - * and the guest will always stay in the halt state, don't - * call the STI instruction (set do_sti as false). - */ const bool irq_disabled = irqs_disabled(); - const bool do_sti = false; - if (__halt(irq_disabled, do_sti)) + if (__halt(irq_disabled)) return -EIO; return ve_instr_len(ve); @@ -261,22 +255,13 @@ static int handle_halt(struct ve_info *ve) void __cpuidle tdx_safe_halt(void) { - /* - * For do_sti=true case, __tdx_hypercall() function enables - * interrupts using the STI instruction before the TDCALL. So - * set irq_disabled as false. - */ const bool irq_disabled = false; - const bool do_sti = true; /* * Use WARN_ONCE() to report the failure. */ - if (__halt(irq_disabled, do_sti)) + if (__halt(irq_disabled)) WARN_ONCE(1, "HLT instruction emulation failed\n"); - - /* XXX I can't make sense of what @do_sti actually does */ - raw_local_irq_disable(); } static int read_msr(struct pt_regs *regs, struct ve_info *ve) |